FightCat

Thanks for the comprehensive answer.

Are we supposed to update mods as their new versions come out via NMM or should we expect a new version of STEP to make sure of which mod version to go with ?

Both the latter, mate.

Done that. No issues. Boy, that was some marathon. Thanks for your help and to those that helped build up the whole thing.

I was able to load a previous save that was at the beginning of a cave which is definitely not far from my end point. So no worries there. Now I'm supposed to get in interiors (e.g. Breezehome) and rest for a total of 31 days before saving for one last time to ensure that our STEP installation has been completed succesfully, right ?

Started a new game without any issues. So we can safely assume that things from the previous saves are not compatible with the current structure of mods. I'll revert back to more previous saves until I find a (hopefully) working one.

Tried a bunch of saves from my on-going game prior to the clean re-installation of Skyrim as STEP instructed to no avail.

Woopsie. I loaded my last save, and it crashed after a while of loading. Any NEW ideas ?

Having started to check the mods recommended one by one in STEP's particular order, the culprit is spotted: Trainer Gold Fix is disabled and I'm in. Weird. Edit: Deactivated TGF. Re-downloaded via NMM, overwrote it, re-activated TGF. I'm able to run it again.

Deleted all ENB files... No luck. Run BOSS, got 1 warning and fixed that. Then run the game through NMM.. No luck. There are only a couple of "contains dirty edits" notifications, that's all. Any ideas ?

And here are the proccesses running and the mods on NMM at the time of the attempts:

It took me 4 days completing all this STEP stuff. I followed the instructions sentence by sentence. Unless the mod was highlighted other than blue, I did not use it however I downloaded and activated them all (in particular order) via NMM. With Project ENB and d39d_smaa.dll (I could grab this from https://mrhaandi.blogspot.com/p/injectsmaa.html as the one indicated in the guide is non-existent) installed, I run the game to see the infamous STEP's results...yet to no avail. As soon as I see the Skyrim Dragon, it crashes. The "crash at startup" recommendations in the guide yielded no results. I don't have Afterburner, GPU-Z, FRAPS running. I have DX updated and the TESV.exe to run in admin mode. Any suggestions please after all this hard work ?